. This project will examine the ability of a recently described protein, Cyr61, to induce localized vascular neoangiogenesis and to develop assays with which to screen specific inhibitors of this activity. Neoangiogenesis plays a critical role in wound healing and also is necessary for tumor growth and metastasis. Thus, therapeutic inhibitors of Cyr61 could be marketable anti-cancer drugs. The specific aims of phase I are the following: (1) demonstration that this protein induces neoangiogenesis in vivo; (2) establishment of an in vitro assay based on this protein's anticipated ability to promote the migration of capillary progenitor cells that can be used to screen rapidly for candidate anti-neoangiogenesis drugs; (3) to identify mammalian cell lines deficient in this protein and to use them to demonstrate the ability of Cyr61 to promote the growth of tumor associated vasculature in vivo. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE